cooling system rover416

[maelorautose]

i have recently put another engine in the 416 and every time it runs on idle for a while it keeps bubbling over, its had a new radiator, new water pump etc, its definately timed right, and ive checked all the hoses for tightness etc

[Brooksy]

what year of manufacture?

[chadad]

I don't know about a " Rover ", But my " Ford " once had the same problem.
It was caused by an air-lock in the cooling system.
This prevents the coolant from reaching the Thermostat so that it doesn't operate until the coolant gets really hot.
Thats when the thermostat opens suddenly and the loss of pressure causes the coolant to bubble up.
( Much the same way as if you open the radiator cap when your engine overheats ,NEVER NEVER DO THIS AT ANY TIME.
The culprit is probably the new thermostat, It should be fitted the right way up and have an air bleed valve in it to allow any air to escape thus letting the coolant reach the correct level.

[maelorautose]

1997

[TWR]

Fan switch faulty, as the other answers, but I hope for your sake it is not the Head Gasket take a tip & get the engine compression tested that will give you the results.

[Blackthorn]

If your engine has an airlock and you can't shift it, try this. I had a Citroen ZX Diesel that defied every attempt at bleeding the air out of the system. On the suggestion of a friend I opened the bleed valves with the engine ticking over, jammed a six foot pipe into the neck of the radiator bottle, (wrapped with insulating tape for a snug fit) and kept on topping up the system keeping the pipe full all the time until the air was forced out.
It looked comical but it worked.

[maelorautose]

blackthorn, i think theres an air leak in there still, but you would think when ive put the cooling filling gun on it, that is suppose to draw all the air out , then fill that this would be soughted . i think i might just try the heater matrix, cos theres no heat coming out, though i have put a brand new thermostat in, and tested it before i put it in.

[petty026]

my car got started to idle at 2000 rpms after I cleaned the engine and changed the oil. Some told me it might be
the moisture in the wire connections that changes the resistance fed to its computer(plasticolor).